Why Xiaomi Redmi smartphone is charging for a long time: a full analysis of the causes and solutions

You plugged in Xiaomi Redmi to charge, but battery percentages crawl like turtles, and instead of the promised 100% per hour, you get +1% in 10 minutes? Slow charging is one of the most common problems among Redmi smartphone owners, but its causes are far from obvious: in some cases, iron (a worn-out battery or a damaged cable) is to blame, in others, MIUI software limitations that users do not even know about.

In this article, we’ll look at 10 key reasons why your Redmi Note 10/11/12, Redmi 9/10 or other model in the series takes too long to charge, and give you step-by-step instructions for diagnosing and fixing the problem. We’ll focus on the hidden MIUI settings that artificially limit charging current — turning them off can speed up the process by 30-50%.

1. Non-original or weak charger

The first thing to check is the power of the charger. Many users use left-handed power units on 5W (standard for older phones), whereas modern Redmi supports Fast Charging on 18W, 33W or even 67W. For example, the Redmi Note 12 Pro+ can charge on 120W, but only with the original adapter.

How do you know which charger your model needs? Focus on the data in the table below. If the unit power is below the specified, the smartphone will charge in normal mode (5W-10W), which is 3-5 times slower.

⚠️ Note: Using chargers from other brands (such as Samsung or Apple) can cause the battery to overheat or activate a protective mode in which the smartphone limits current to the power supply. 5W. This applies even to adapters with the right power, but without support for Quick Charge or Power Delivery.

2. Damaged cable or USB connector

Even with a powerful adapter, charging can be slowed down because of a damaged cable, and over time, the wires inside the wires are rubbed, especially at the base of the connector, and visually, the cable may look whole, but inside the torn veins, which are responsible for data transmission or power.

How to check the cable:

• 🔍 Check the connector for darkening, melting or rust (especially in Micro-USB).
• 📱 Try to slightly move the cable in the smartphone connector – if the percentage of charging “jumps”, the problem is contacts.
• 🔄 Connect the cable to another device (such as a power bank) and check the charging speed.
• 🛠️ Use a tester or multimeter to check resistance (should be close to 0 ohms).

⚠️ Attention: If the connector USB-C Or Micro-USB on your smartphone is wobbly or contaminated, which can lead not only to slow charging, but also to short circuit. Clean the connector with only a dry toothpick - metal objects or wet wipes will damage the contacts!

3. Functions on which the charging brake is

MIUI has several "hidden" features that artificially limit charging speeds. Their goal is to extend battery life, but they often work overly aggressively, especially on Redmi's budget models.

What settings to check:

• 🔋 Optimized charging (Settings) → Battery → Battery settings: If turned on, the smartphone will charge up to 80% very quickly, and then “get” the last 20% 2-3 times slower.
• 🌡️ Thermal control (Settings) → Battery → Temperature control: overheating (above 40)°C) or refrigeration (below 0)°C) the charging speed shall fall to 5W.
• 📵 Energy saving mode (Settings) → Battery → Power saving mode: limits background processes, but also reduces charging current.
• 🔄 Background activity of apps: if Google Maps, Telegram or games are running while charging, some of the energy goes to them, not the battery.

💡 If you need to charge your smartphone urgently, turn off mobile internet and Wi-Fi while you’re charging, which will reduce the processor load and allow the battery to charge 10-15% faster.

4. Worn-out battery

The Lithium Polymer batteries in Xiaomi Redmi smartphones are designed for 500-800 charging cycles. After that, their capacity drops by 20-30%, and the charging speed decreases by 1.5-2 times. For example, if your Redmi Note 10 Pro used to charge in 1 hour, then in 2 years it can spend 2-2.5 hours on it.

How to check the wear of the battery:

1. Install the AccuBattery app (available on Google Play).
2. Charge your smartphone to 100% and discharge to 0% (no recharging!).
3. Look at the battery health parameter in Health, below 80% indicates critical wear.

⚠️ Warning: If the battery capacity has fallen below 70%, it must be replaced:

• ⚡ Sudden shutdowns at 10-20% charge.
• 🔥 Risk of bloating and damage to internal components.
• 🐢 Even slower charging (due to increased internal resistance).

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Replacing the battery in the service center costs 1.5-3 thousand rubles (depending on the model), self-replacement is fraught with loss of tightness and dust under the screen.

5. Software failures and MIUI errors

Sometimes slow charging is not due to hardware, but to software bugs in the firmware. For example, after the update of MIUI 13 → MIUI 14, many Redmi Note 11 users complained that the smartphone stopped recognizing fast charging, due to errors in the drivers of the power controller.

How to fix it:

• 🔄 Reboot your smartphone – sometimes it resets time limits.
• 📲 Clear the system cache: go to Settings → Memory. → Cleanup → Cash and press Clear.
• 🔧 Reset the battery settings: Settings → Battery → ⋮ (menu) → Resetting battery settings.
• 🔄 Reverse to the old version MIUI (If the problem has appeared after the update. To do this, download the firmware from the official Xiaomi website and run through Fastboot.

💡 Useful tip: If after resetting the battery settings, the charging speed normalized, but after a few days fell again, try turning off automatic optimization in Settings → Battery → Battery settings → Optimizing charging.

6.Use of a smartphone while charging

Many users do not realize that the active use of Redmi during charging can reduce its speed by 2-3 times, the fact that the energy from the charger is spent not only on replenishing the battery, but also on:

• 🎮 Games (especially Genshin Impact, PUBG Mobile – they load the processor on 80-100%).
• 📹 Video calls (Zoom, WhatsApp) – the camera and screen are consumed by the user 3W.
• 🗺️ Navigation (Google Maps, Yandex.Maps) — GPS-Module and mobile Internet increase consumption.
• 🔊 Playing music/video via Bluetooth or speakers.

📊 Test: Connect Redmi to charge and start the game. Compare the charging speed to what the smartphone shows in standby mode. The difference can be as high as 50%!

⚠️ Note: If you play while charging, the smartphone may overheat, which will lead to an automatic reduction in current to 5W. In the worst case, the battery is swelling.

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To speed up charging, turn on the plane mode or at least turn off mobile data and Wi-Fi, which will reduce the load on the processor and allow the battery to charge faster.

7. Problems with firmware or custom software

If you installed custom firmware (like LineageOS, Pixel Experience) or rooted your smartphone through Magisk, it could have affected the charging controller. Incorrect cores or modified drivers often lead to:

• 🔌 Lack of support for Fast Charging.
• 📉 Unstable current (jumping from the 5W before 18W).
• 🔋 Incorrect display of percentage of charging.

How to diagnose:

1. Install the Ampere app (or AccuBattery) and check the actual charging current.
2. Compare the figures with your model’s passport data (see table in section 1).
3. If the current is lower than expected, try returning to stock firmware via the Mi Flash Tool.

💡 Key takeaway: Castom firmware is often optimized for performance, not energy efficiency. If after firmware, the smartphone began to charge slower, but longer holds charge - this is normal behavior.

External factors: temperature and humidity

Lithium polymer batteries are extremely sensitive to ambient temperature. Xiaomi says the optimal range for charging is 10-35°C. When you go beyond these limits, the smartphone automatically reduces the current:

• ❄️ Low 0°C: Charging can be completely turned off (risk of electrolyte damage).
• 🔥 Above 40.°C: current drops to 5W, A warning appears on the screen: “Battery temperature is too high».
• 💦 High humidity (over 80%): can cause corrosion of connector contacts.

How to avoid problems:

• 🚫 Do not charge your smartphone in the direct sun (for example, on a car torpedo).
• 🏠 In winter, let the phone heat up to room temperature before charging.
• 🔋 Don’t use power bank in the cold – they also lose their efficiency.

⚠️ If the smartphone overheats for no apparent reason (do not play, do not use the navigator), this may indicate a serious problem:

• 🔋 Faulty battery (swelling, short circuit).
• 🛠️ Problems with the motherboard (burnt power controller).
• 🦠 Viruses or mining software (check out Malwarebytes).

FAQ: Frequent questions about slow charging Xiaomi Redmi